Currently, pricing of items is shown by item tags attached to an item or to a shelf near a collection of items Item tags are typically printed with inks using thermal, impact or inkjet processes. Such printing creates an unchanging display of a price Electronic Shelf Labels (ESL) from IBM, National Cash Register and Fujitsu provide glass liquid crystal displays to present pricing information that can be electronically updated. Commercial Electronic Shelf Labels use conventional TN displays that require continuous electronic refreshing to display data The continuous refreshing requires refreshing electronics and a battery Printed labels are attached to a rigid substrate of the ESL to provide a display of unchanging universal product code (UPC) and product description. Current ESLs update pricing information using radio waves or light to transmit updated pricing information to a specific label.
Media systems exist that maintain electronically changeable data without power. Such system can be electrophoretic (Eink), gyricon or polymer dispersed cholesteric materials. An example of electronically updateable display can be found in U.S. Pat. No. 3,600,060 issued Aug. 17, 1971 to Churchill et al. that shows a device having a coated then dried emulsion of cholesteric liquid crystals in aqueous gelatin to form a field responsive, bistable display.
Fabrication of flexible, electronically written display sheets is disclosed in U.S. Pat. No. 4,435,047 issued Mar. 6, 1984 to Fergason. A first sheet has transparent ITO conductive areas and a second sheet has electrically conductive inks printed on display areas The sheets can be glass, but in practice have been formed of Mylar polyester. A dispersion of liquid crystal material in a binder is coated on the first sheet, and the second sheet is pressed onto the liquid crystal material. Electrical potential applied to opposing conductive areas operates on the liquid crystal material to expose display areas. The display ceases to present an image when de-energized.
U.S. Pat. No. 5,751,257 issued May 12, 1998 to Sutherland discloses an electronic shelf label using a display that has first and second rigid substrates, with the bottom substrate protruding beyond the top substrate to provide access to conductors on the bottom substrate Cholesteric material in the proposed display provides pricing information that does not require refresh electronic or a power source Connection to a common conductor on the top substrate is provided by an extension arm having an electrical contact that makes contact with the conductor on the underside of top substrate Segments of the display are updated by rolling a second contact across sequentially arrayed contacts on the bottom substrate.
Stores update pricing of items frequently. Printed tags must be continually replaced to provide updated information. Electronic tags are expensive, and currently are built into rigid assemblies. It would be useful to have an image of the item printed onto an item tag. Unfortunately, image printing is expensive for disposable tags. Electronically re-writable displays cannot be passed through conventional printing systems such as inexpensive ink jet printers.
There is a need therefore for an inexpensive display structure that can be electronically re-written and receive a printed image of the item for sale. It is of further utility that the tag be flexible to pass through conventional ink jet printers